Diode-pumped 1.4-w Tm3+:GdVO4 microchip laser at 1.9 μm

GdVO4 as a host for thulium has several advantages for diode pumping in comparison with other crystals, The absorption cross section of thulium in GdVO4 is considerably stronger and broader than in YAG and YLF, and the spectrum is shifted closer to the emission wavelength of commercially available AlGaAs laser diodes. In our paper, we report on a diode-pumped monolithic Tm3+(6.9 at.%):GdVO4 microchip laser at 1.9 mu m A maximum output power of 1.4 W is achieved. Two different arrangements for cooling the crystal are discussed. Furthermore, the input-output curves under Ti:sapphire pumping are compared for different pump wavelengths, Slope efficiencies of 58%, clearly exceeding the Stokes limit of 41%, are achieved.